unxfail test_keyboard as it has been passing for several builds
Merge pull request #751 from bobsilverberg/unxfail_keyboard

unxfail test_keyboard as it has been passing for several builds
test_marketplace_login use marketplace-dev app
updated according review
Merge pull request #754 from AndreiH/mp_login_use_mp_dev

test_marketplace_login.py uses Marketplace-dev app
test_search_mp_and_install_app to use MP dev app
Merge pull request #758 from AndreiH/mp_login_use_mp_dev

test_search_mp_and_install_app to use MP dev app